As you get older, your risk for most diseases will increase. Since prevention is an enormous part of the “solution”, watching your diet is even more important than ever. But of course, you also need fewer calories at this time, too. That’s why nutritionists discourage “empty calories” from junk food, and encourage you to pack as many nutrients as possible into your meals. In particular, watch your intake of the following nutrients.

Fiber. Fiber promotes healthy digestion and can protect against diseases like colon cancer, but most of us are only eating about half of the recommended amount of fiber. Fiber supplements can help, but you should be eating a diet rich in fruits, vegetables, beans, and whole grains anyway.

Omega-3 Fats. Not all fats are bad. In fact, Omega-3 fats can keep your brain sharp, reduce the risk of Alzheimer’s, slow the progression of macular degeneration, and improve the symptoms of rheumatoid arthritis. Fish, walnuts, soybeans, and certain oils are high in Omega-3 fats. You might also ask your doctor about supplementation if you eat a limited diet for some reason.

Calcium. Bones often become brittle as we age, leaving us more prone to fractures. Calcium can help keep your bones strong, so include it in your daily diet and take a supplement if you’re at high risk for conditions like osteoporosis.

Vitamin D. Since vitamin D helps the body absorb calcium, it will help to protect your bones. Vitamin D is also thought to protect against cancer, diabetes, auto-immune diseases, rheumatoid arthritis, and multiple sclerosis. Your body generates vitamin D when you’re exposed to sunlight, but it is also added to many foods.

Folic Acid. Those who are deficient in folic acid often suffer from anemia. Check food labels to see if your breads and cereals are fortified, and eat plenty of fruits and vegetables.

Vitamin B12. Most older people have a hard time absorbing vitamin B12 from foods, but it’s vitally important to healthy nerve function. If you aren’t packing your daily regimen full of B12-rich foods, talk to your doctor about a vitamin supplement.

Potassium. Potassium is another nutrient that promotes healthy bones, and can also protect you against kidney stones and high blood pressure. Eat fruits and vegetables like bananas, potatoes, prunes, and plums. Talk to your doctor before taking potassium supplements, because in this case too much of a good thing can actually be bad for you.

Magnesium. As you get older, your body has a harder time absorbing magnesium from foods. You might also be prescribed certain medications, such as diuretics, that can worsen the problem. Make sure to eat foods high in magnesium (nuts, whole grains, fruits, vegetables, beans, and seeds) to protect your bones, keep your heart healthy, and promote a vigorous immune system.

Water. It’s not exactly a “nutrient”, but water is of course the most important thing that we consume every day. Older adults often feel fewer thirst signals, and are at high risk for dehydration. So purchase a refillable water bottle, and put yourself on a water-drinking regimen. You should be drinking about 64 ounces of water per day.

As always, consult with your doctor before making any major changes to your diet. He or she can screen you for nutritional deficiencies, and make specific recommendations to keep you healthy.